1. Field of the Invention
The present invention relates to a piezoelectric microphone, a speaker, a microphone-speaker integrated device, and a manufacturing method thereof, and more particularly, to a microphone with a pattern structure for enhancing efficiency of a piezoelectric microphone having a mating structure, a speaker having a differentially etched piezoelectric plate and a series/parallel mating electrode, a microphone-speaker integrated device, and a manufacturing method thereof.
This work was supported by the IT R&D program of MIC/IITA. [2006-S-006-02, Component Module for Ubiquitous Terminal]
2. Discussion of Related Art
Technology for miniaturizing a microphone and a micro-speaker on a silicon wafer has been disclosed. The disclosed method of manufacturing an acoustic transducer on a silicon wafer reduces costs since the manufacture can be performed by batch processing, and miniaturizes the device because a plurality of transducers and amplifiers can be integrated on a single chip, thereby having many advantages over other conventional methods.
However, the piezoelectric-type acoustic transducer has the problems that the microphone has a relatively low sensitivity due to tensile residual strain in a transducer vibration plate, and the micro-speaker has a low output. To solve these problems, there has been proposed a voice converting apparatus using a mating electrode instead of a piezoelectric voice converting apparatus using conventional upper and lower electrodes.